Help with PR's Kaiser Rolls

Hey everybody, quick question.  I'm making some rolls for bridal shower.  They want some Dill/Onion rolls.  I tried the James Beard sour cream bread as a roll, it was okay, but I like PR's Kaisers much better!  Can I just add some dried onions and dill to the mix and use that recipe instead?  What if I want to make Bacon, Cheddar, rolls too?  How much should I add, and should I just put it in when I mix the dough together at first?  Also if I re-hydrate the onions, should I use that water for the bread?  I heard someone say that was good?  Anyways, would appreciate any input!  Thanks a bunch!

Faith